Etzel Cardeña experiments and data

Question

ESP-Nexus Discovery Lab · Accepted Answer

Etzel Cardeña is a researcher based at Lund University in Sweden, where he holds an appointment connected to the Center for Research on Consciousness and Anomalous Psychology (CERCAP) ^[3]^[4]. The sources retrieved for this question touch on several distinct areas of his work.

Research Areas

Near-Death Experiences

Cardeña co-authored a phenomenological study of distressing near-death experiences (NDEs) with Amal Ait Melloul and Karolina Kinnunen ^[2]. The study drew on narratives of hellish or otherwise distressing NDEs and examined both the experiential content and the aftereffects — including post-experience anxiety, restlessness, and difficulties processing the experience without social support. The methodology was qualitative, accessing existing NDE narrative accounts rather than running a controlled lab paradigm.

Precognition and Replication Research

Cardeña is listed as a co-author on a large multi-experimenter replication effort examining Daryl Bem’s time-reversed priming paradigm ^[5]. That 2021 paper involved researchers from multiple institutions running two replication studies. Key figures from the source:

Finding	Statistic
Bem’s original nine experiments (2011) — mean effect size	d = 0.22, Stouffer’s z = 6.66, p = 1.34 × 10⁻¹¹
Follow-up meta-analysis of 15 precognitive priming experiments (Bem et al., 2016)	d = 0.11, p = 0.003
Meta-analytic result with Bem’s original studies excluded	ES = 0.06, z = 4.16, p = 1.1 × 10⁻⁵, BF = 3.85

The replication paper’s own authors frame the results as open to two competing interpretations: the original Bem findings reflected a genuine psi effect that the replication conditions disrupted, or the original findings were false positives arising from exploratory analysis and low power ^[5]. The paper does not adjudicate between these.

An earlier analysis of 60 independent psi experiments (1945–1983) cited within this paper found a small correlation between extraversion and psi performance (r = 0.09, z = 4.63, p = 0.000004), attributed to Honorton et al. (1992) — a variable the replication team examined but found no support for in their own data ^[5].

Editorial and Commentary Work

Cardeña edited (with John Palmer and David Marcusson-Clavertz) a handbook on parapsychology that appears in the sources as a cited reference [3 via the Berger page]. He has written book reviews in the Journal of Scientific Exploration, including reviews engaging with skeptical and pro-parapsychology literature ^[3]^[4]. His 2018 review in American Psychologist is cited on the ESP-Nexus pages for Roger D. Nelson and Dean I. Radin as a mainstream-journal survey of experimental parapsychology evidence, though the text of that review is not among the retrieved sources for this question.

He is also acknowledged in Michael Nahm’s 2021 investigation of scientific misconduct in parapsychology as one of several colleagues who provided support during that work ^[6] — a minor acknowledgment, not a research contribution.

Scholarly Commentary on Integrity

His 2021 commentary on the Alejandro Parra plagiarism and data fabrication case ^[1] situates him as a participant in the field’s self-policing discourse, though the commentary itself is brief and the retrieved excerpt does not contain extended empirical content.

Skeptical Critiques

What critics argue. The multi-experimenter replication of Bem’s priming paradigm — on which Cardeña is a co-author — was itself motivated by critiques that Bem’s (2011) original nine experiments involved partly exploratory analyses (Wagenmakers et al., 2011) and were underpowered (Schimmack, 2012), conditions that can generate false positives ^[5].

What the experimental data show. The 2021 replication study found that neither of the two replication attempts fully reproduced Bem’s original effect. At the same time, the broader meta-analytic literature (excluding Bem’s originals) still returned a statistically significant result, ES = 0.06 ^[5]. The replication paper itself acknowledges both that replication failures are hard to interpret definitively and that the exploratory-analysis critique of the originals has not been resolved.

Analysis. The paper Cardeña co-authored is notable for including researchers who hold divergent priors on psi — the author list spans proponents, skeptics, and agnostics. Neither replication succeeded in reproducing the original effect size; the authors name this plainly and offer no resolution between the two interpretations ^[5]. Independent replication of the full Bem effect at its original magnitude has not been established in the literature the retrieved sources describe.

The ESP-Nexus Scientists section is the best starting point for deeper coverage of researchers whose work intersects with Cardeña’s, including Dean I. Radin and Roger D. Nelson, both of whose pages reference Cardeña’s 2018 American Psychologist review.